SMF-AR
SMF-AR stands for Sintered Metal Filter with Active Regeneration. The SMF-AR system
uses fuel-borne catalyst to enable the passive regeneration, and this causes the
accumulated DPM to burn once the exhaust gas temperature exceeds about 350C. The
fuel-borne catalyst is stored in a separate tank and automatically dosed into the
fuel tank whenever the vehicle or machine is refuelled. The active part of the system
consists of an electrical heating element which radiates heat onto the filter until
the accumulated DPM starts to burn. The heater element is automatically switched
on whenever the exhaust backpressure exceeds 200 mbar. The filter element is unusual
in that it is made from sintered metal rather than the more common silicon carbide
or cordierite. The main advantages of using sintered metal are that it conducts
heat better than the alternative materials and also has a lower heat capacity. This
enables the heating element to rapidly ignite the DPM and the combustion process
to spread throughout the filter. Other advantages are lower exhaust backpressure
and improved durability. The SMF-AR system has a compact display panel to convey
essential information to the driver, and also stores data which can be checked by
a technician at the next service interval. Apart from topping up the fuel-borne
catalyst tank the only service requirement is to remove ash from the filter when
advised to do so by the display panel (typical interval 1000-2000 hours).
The SMF-AR system is suitable for a wide range of engine sizes, with either 12 or
24 volt electrics, and unlike some other systems, is not sensitive to the sulphur
content of the fuel. One-off installations are carried out on site by our own engineers,
however in the case of volume orders we can train the customer’s own staff to install
it and can also supply the fitting kit, wiring harness etc customised for the particular
application. The SMF-AR system has been tested and approved by VERT (the Swiss environmental
regulator) and several thousand systems are now in use around the World.
(Diagram: Schematic diagram of SMF-AR)